Shoe wear-out sensor, body-bar sensing system, unitless activity assessment and associated methods

ABSTRACT

A system assesses activity and displays a unitless activity value. A detector senses activity of a user. A processor reads sensed activity data from the detector. A display displays the unitless activity value. An enclosure houses the detector and the processor. The processor periodically reads the sensed activity data from the detector and processes the data to generate an activity number, the number being used to generate the unitless activity value based upon a maximum number and a display range.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/544,733 filed Jul. 9, 2012 (now U.S. Pat. No. 8,749,380), which is acontinuation of U.S. patent application Ser. No. 13/034,311 filed Feb.24, 2011 (now U.S. Pat. No. 8,217,788), which is a continuation of U.S.patent application Ser. No. 12/083,726 (now U.S. Pat. No. 7,911,339),which is a 35 U.S.C. §371 National Phase entry of International PatentApplication No. PCT/US2006/040970 filed Oct. 18, 2006, which claimspriority to U.S. Provisional Patent Application No. 60/728,031 filedOct. 18, 2005. All of these earlier applications are incorporated hereinby reference.

BACKGROUND

Shoes (including sneakers or boots, for example) provide comfort andprotection for feet. More importantly, shoes provide physical supportfor feet to reduce risk of foot injuries. A shoe is often necessary toprovide support during intense physical activity, such as running,soccer and American football. As a shoe wears, physical support providedby the shoe decreases, thereby reducing associated protection frominjury. When a critical wear level is reached, even if the shoe lookslike it is not particularly worn, the shoe may not provide adequatesupport and may, in fact, cause damage to feet.

SUMMARY

In one embodiment, a shoe wear out sensor includes at least one detectorfor sensing a physical metric that changes as a shoe wears out, aprocessor configured to process the physical metric, over time, todetermine if the shoe is worn out, and an alarm for informing a user ofthe shoe when the sole is worn out.

In another embodiment, a system determines the end of a shoe's life. Useof the shoe is sensed by at least one detector. A processor isconfigured to measure the use of the shoe and to determine if the shoeis worn out. An alarm informs a user of the shoe when the shoe is wornout.

In another embodiment, a body bar sensing system includes a housing withat least one detector for sensing a physical metric that indicatesrepeated movement of the housing when attached to the body bar, aprocessor configured to process the physical metric, over time, todetermine repetitions thereof, and a display for informing a user of therepetitions.

In another embodiment, a system assesses activity and displaying aunitless activity value and includes a detector for sensing activity ofa user of the system, a processor for processing sensed activity datafrom the detector, a display for displaying the unitless activity value,and an enclosure for housing the detector and the processor. Theprocessor periodically reads the sensed activity data from the detectorand processes the data to generate an activity number, the number beingused to generate the unitless activity value based upon a maximum numberand a display range.

In another embodiment, a method determines a unitless activity value fora desired period of activity. A period accumulator is cleared prior tothe start of the activity period. A detector is periodically sampled toobtain data that is processed to determine a number representative ofthe sampling period. The number is added to the period accumulator. Theunitless activity value is then determined based upon the periodaccumulator, a maximum activity number and a display range. The unitlessactivity value is then displayed. The sampling, processing and addingare repeated until data is sampled for the desired period of activity.

In another embodiment, a method assesses activity unitlessly bydetecting motion of a user, processing the detected motion, over time,to determine an activity value, ratioing the activity value to a maximumactivity value, and reporting a scaled unitless activity value to theuser based upon the ratio and a scale.

A software product has instructions, stored on computer-readable media,that, when executed by a computer, perform steps for determining aunitless activity value for a desired period of activity, includinginstructions for: detecting motion of a user, processing detectedmotion, over time, to determine an activity value, ratioing the activityvalue to a maximum activity value, and reporting a scaled unitlessactivity value to the user based upon the ratio and a scale.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows one exemplary embodiment of a shoe wear-out sensor.

FIG. 2 shows one exemplary embodiment of a shoe with a shoe wear outsensor.

FIG. 3 shows another exemplary embodiment of a shoe with a shoe wear outsensor.

FIG. 4A shows one exemplary process for determining shoe wear out.

FIG. 4B shown one exemplary process for determining shoe wear out.

FIG. 4C shows one exemplary process for determining shoe wear out.

FIG. 4D shown one exemplary process for determining shoe wear out.

FIG. 5 shows one body bar sensing system embodiment.

FIG. 6 shows one part of an exemplary body bar with a body bar sensingsystem embodiment attached.

FIG. 7 shows one part of a body bar in an embodiment showing a weightand a body bar sensing system that secures the weight onto the body bar.

FIG. 8 shows one exemplary process for reporting body bar usage.

FIG. 9 shows an embodiment of a sensor that unitlessly assessesactivity.

FIG. 10 shows a process for unitlessly determining activity.

DETAILED DESCRIPTION OF THE FIGURES

FIG. 1 shows one shoe-wear out sensor 100. Sensor 100 includes aprocessor 102, a detector 104 and an alarm 106. A battery 108 may beused to power processor 102, detector 104 and alarm 106; alternatively,a magnetic coil generator (not shown) or other mechanicalmotion-to-electricity conversion device may be employed with sensor 100to power these elements. Detector 104 is for example an accelerometerand/or a force sensing resistor (FSR). Alarm 106 is for example a lightemitting diode (LED) and/or a small speaker and/or a small soundactuator (e.g., a buzzer, piezoelectric beeper etc).

FIG. 2 shows a shoe 200 with a shoe-wear out sensor 210. Shoe 200 is forexample a running or sport shoe, boot (e.g., a snowboard or hikingboot), slipper, dress shoe or flip-flop; shoe 200 may alternatively bean orthopedic shoe for providing special foot support. Sensor 210 mayrepresent sensor 100, FIG. 1. In the illustrated embodiment, shoe 200has a sole 202 and an upper part 204. Sole 202 has an outsole 206 and aheel 208. Sensor 210 is shown contained within heel 208; however sensor210 may be placed elsewhere within or on the shoe to function similarly.

FIG. 3 shows one exemplary embodiment of a shoe with a shoe-wear outsensor 310. Sensor 310 may again represent sensor 100, FIG. 1. Shoe 300is shown with a sole 302 and an upper part 304. Sole 302 has an outsole306 and a heel 308. Shoe 300 may again represent, for example, a runningshoe, sports shoe or orthopedic shoe (or other type of shoe or boot).Electronics 310 a of sensor 310 are shown contained within heel 308; butdetector 312 is shown located within outer sole 306, illustrating thatthe elements of sensor 100 (FIG. 1) may be dispersed to variouslocations of the shoe while providing similar functionality. Detector312 is for example detector 104, FIG. 1; it may thereby be a forcesensing resistor and/or a piezoelectric foil that is electricallyconnected, via connection 314, to electronics 310 of sensor 310. Ifdetector 312 is a piezoelectric foil (or other piezoelectric device),use of shoe 300 results in flexing of detector 312 which may generatesufficient electricity to power electronics 310 a of sensor 310,avoiding the need for battery 108.

FIGS. 1, 2 and 3 are best viewed together with the followingdescription. Sensor 100 may be embedded in a shoe (e.g., sensors 210,310 within shoes 200, 300) and configured to determine when that shoehas “worn out”. It then informs the user, via alarm 106, that it is timeto buy a new shoe (usually a new pair of shoes). In an embodiment, alarm106 is an LED 217 that is positioned at the outside of the shoe suchthat it may be seen, when activated, by the user of the shoe, asillustratively shown in FIG. 2.

Processor 102 may operate under control of algorithmic software 103(which is illustratively shown within processor 102, though it mayreside elsewhere within sensor 100, for example as stand alone memory ofsensor 100). Algorithmic software 103 for example includes algorithmsfor processing data from detector 104 to determine when a shoe is wornout.

FIG. 4A for example illustrates one process 400 performed by processor102 of FIG. 1. In step 402, processor 102 samples detector 104 todetermine a physical metric associated with the shoe. In an example ofstep 402, detector 104 is an accelerometer and thereby providesacceleration data resulting from movement of the shoe upon a surface asthe physical metric. For example, as the shoe strikes the ground when inuse, processor 102 takes a plurality of samples using detector 104 toform an impact profile. In step 404, processor 102 processes thephysical metric and compares it against a predetermined threshold,response curve or other data reference. In an example of step 404,processor 102 compares the impact profile determined from theaccelerometer against an impact profile of a “new” shoe. In anotherexample of steps 402, 404, the physical metric is power spectral densitycorresponding to certain frequencies of interest; and the power spectraldensity is compared, during use of the shoe, to a data referencecontaining power spectral density of a new or acceptably performingshoe. If the current data (i.e., physical metric) is too large orexceeds the data reference, for example, then processor 102 sets offalarm 106 (e.g., lights LED 217) in step 406. In one embodiment, uponfirst use of the shoe, processor 102 determines an impact profile of thenew shoe that is then used (e.g., as the threshold or data reference) incomparison against subsequently determined impact profiles. Or, uponfirst use of the shoe, for example, processor 102 may store theappropriate data reference (e.g., power spectral density or threshold)for comparison against data captured in latter uses of the shoe. In thisway, therefore, process 400 may be efficiently used to inform a user ofshoe wear out.

As noted, data from detector 104 may be processed in the frequencydomain (e.g., using Fourier transforms of data from detector 104) so asto evaluate, for example, power spectral density of the physical metric(e.g., acceleration or force), in step 404. In this manner, therefore, arange of frequencies may be evaluated (e.g., an area under the curve forcertain frequencies may be integrated) from detector 104 and thencompared to similar data (as the threshold) of a new shoe. As a shoewears, the elasticity of the material from which it is made changes;thus the ability of the material to absorb the shock of the shoecontacting the ground deteriorates, resulting in more shock force beingtransferred to the foot within the shoe. By determining the increase ofthe shock force above the threshold, in this embodiment, the wear on theshoe may be determined.

We now specifically incorporate by reference the teachings anddisclosure of: U.S. Pat. No. 6,539,336; U.S. Pat. No. 6,266,623; U.S.Pat. No. 6,885,971; U.S. Pat. No. 6,856,934; U.S. Pat. No. 6,8963,818;U.S. Pat. No. 6,499,000; and U.S. Pat. No. 8,280,682. These patents andapplications provide useful background, power sensing andweight/movement monitoring techniques suitable for use with theteachings of this present application.

In an embodiment, similar to the embodiment of FIG. 3, processor 102determines wear of shoe 300 based upon weight of the user of shoe 300.By using signals from detector 312 to determine an approximate weight ofthe user of shoe 300 (for example by using a pressure sensor andfluid-filled cavity as detector 104), processor 102 may determine a lifeexpectancy of shoe 300. Since the wear on the shoe is roughlyproportional to the weight applied by the wearer, during activity, bydetermining the weight of the wearer and the amount the shoe is used(e.g., how often and how long the shoe is used), processor 102 may thusdetermine shoe wear with increased accuracy. That is, a shoe used bysomeone who spends most of their time sitting at a desk receives lesswear that a shoe used by someone who spends most of the day standing ontheir feet.

In another embodiment, by sensing when the shoe is used—or for howlong—the teachings herein may instead be applied so as to set off thealarm after a term or time of use has expired. For example, if a shoe isspecified for use to at least 100 hours or 500 miles (or other similarmetric specified by the shoe manufacturer), then by sensing weight oracceleration (or other physical metric, via detector 104) that use maybe determined; processor 102 then activates alarm 106 when the use isexceeded. For example, using one or more accelerometers as detector 104,speed of the shoe may be determined through operation of processor 102using an appropriate algorithm within software 103; this processor 102then uses the speed information to determine distance traveled and setsoff alarm 106 when, for example, the manufacturer's specified distanceuse is met. Illustratively, in another example, if the manufacturerspecifies that the shoe may be used under normal conditions for 500hours (or some other time), then detector 104 in the form of anaccelerometer may determine when the shoe is in use; processor 106 thendetermines the period of use, over time (e.g., weeks and months) andsets off alarm 106 when the accumulated use exceeds the specified limit.

FIG. 4B for example illustrates one process 450 performed by processor102 of FIG. 1 for determining shoe wear out. In step 452, processor 102samples detector 104 to determine one or more physical metricsassociated with the shoe. In an example of step 452, detector 104includes a fluid filled cavity and a pressure sensor and therebyprovides a signal representative of force upon the shoe (e.g., a valuerepresentative of the weight of the user of the shoe). For example, asthe shoe is used, processor 102 takes a plurality of pressure readingfrom detector 104. In step 454, processor 102 determines an approximateweight upon the shoe based upon samples of step 452. In one example ofstep 454, processor 102 utilizes algorithms of software 103 to determinean approximate weight of the user of the shoe based upon pressure valuessensed by detector 104. In step 456, processor 102 determines theduration of the shoe's use. In one example of step 456, processor 102utilizes algorithms of software 103 to measure the duration that theshoe is used based upon readings from detector 104 and an internal timerof processor 102. In step 458, processor 102 determines the shoe use forthe sample period of step 452. In one example of step 458, processorutilizes algorithms of software 103 to determine a use factor based uponthe determined weight of step 454 and the duration of use of step 456.In step 460, processor 102 determines remaining life of the shoe basedupon the determined shoe use of step 458. In one example of step 460,processor 102 maintains a cumulative value of usage determined in step458 for comparison against a manufacturer's expected usage of the shoe.In step 462, processor 102 enables alarm 106 if the shoe's life isexceeded. Steps 452 through 462 repeat periodically throughout the lifeof the shoe to monitor shoe usage based upon wear determined from theweight of the user and the duration of use.

In the above description of process 450, it is not necessary that weightbe determined. Rather, in an embodiment, it may instead be determinedthat the shoe is “in use” based on an algorithm using the pressure orforce based detector 104; and then this use is accumulated time-wise todetermine when the shoe's life expectancy is exceeded. For example, oncea user puts weight onto this detector (in this embodiment), thenprocessor 102 detects (through use of an algorithm as software 103) thatthe shoe is in use due to the presence of weight onto detector 104.

FIG. 4C for example illustrates one process 470 performed by processor102 of FIG. 1 for determining shoe wear out. In step 471, processor 102samples detector 104 periodically over a defined period. In one exampleof step 471, detector 104 is an accelerometer that is sampledperiodically by processor 102 over a period of ten seconds. In step 472,processor 102 determines if the shoe is in use. In one example of step472, processor 102 utilizes algorithms of software 103 to process thesamples of step 471 to determine if the shoe is in use. Step 473 is adecision. If, in step 473, processor 102 determines that the shoe is inuse, process 470 continues with step 474; otherwise process 470continues with step 475. In step 474, processor 102 adds a valuerepresentative of the defined period of step 471 to an accumulator. Inone example of step 474, a non-volatile accumulator is incremented byone, where the one represents a period of ten seconds. Step 475 is adecision. If, in step 475, processor 102 determines that the shoe isworn out, process 470 continues with step 476; otherwise process 470continues with step 471. In one example of the decision of step 475,processor 102 compares the use accumulator of step 474 against a valuerepresentative of the expected life of the shoe. Steps 471 through 475repeat throughout the lifetime of the shoe. As appreciated, power savingmeasures may be used within sensor 100 when it is determined that theshoe in which sensor 100 is installed is not in use. In step 476,processor 102 enables alarm 106. In one example of step 476, processor102 may periodically activate LED 217, FIG. 2, until battery 108 isexhausted.

Process 470 thus determines the wear on a shoe by measuring the amountof use and comparing it against the expected use defined by amanufacturer, for example. In an embodiment, the use accumulator of step474 is a timer within processor 102. This timer is started when step 473determines that the shoe is in use and is stopped when step 473determines that the shoe is not in use. This timer thus accumulates, inreal time, the use of the shoe for comparison against a manufacturer'sexpected use. In another embodiment, step 472 may determine the numberof steps a shoe has taken such that the use accumulator of step 474accumulates the total number of steps taken by the shoe. This totalnumber of steps is then compared to the manufacturer's recommendednumber of steps expected in the shoes life time.

FIG. 4D illustrates one process 480 performed by processor 102 of FIG. 1for determining shoe wear out. In step 481, processor 102 samplesdetector 104 periodically over a defined period. In one example of step481, detector 104 is an accelerometer and processor 102 samplesacceleration values over a period of 1 second. In step 482, processor102 determines if the shoe is in use. In one example of step 482,processor 102 utilizes algorithms of software 103 to determine ifcharacteristics of samples values of step 481 indicate that the shoe isin use. Step 483 is a decision. If, in step 483, processor 102determines that the shoe is in use, process 480 continues with step 484;otherwise process 480 continues with step 486. In step 484, processor102 determines a distance traveled over the defined period of step 481.In one example of step 484, processor 102 utilizes algorithms ofsoftware 103 to first determine speed of the shoe, and then determinesdistance covered in one second. In step 485, processor 102 accumulatesthe distance traveled. In one example of step 485, processor 102 addsthe distance determined in step 484 to a total distance traveledaccumulator. In one example, this accumulator is stored in non-volatilememory. Step 486 is a decision. If, in step 486, processor 102determines that the shoe is worn out, process 480 continues with step487; otherwise process 480 continues with step 481. In one example ofstep 486, processor 102 compares the total accumulated distance of step485 against the manufacturer's recommended maximum distance for theshoe. Steps 481 through 486 repeat throughout the lifetime of the shoe.As appreciated, power saving measures may be used within sensor 100 whenit is determined that the shoe is not in use. In step 487, processor 102enables alarm 106. In one example of step 487, processor 102 mayperiodically activate LED 217, FIG. 2, until battery 108 is exhausted.Process 480 thus determines shoe wear by measuring the distance traveledby the shoe, using one or more accelerometers, and compares thatdistance to a manufacturer's recommended maximum distance for the shoe.

FIG. 5 shows a body bar sensing system 500. System 500 includes ahousing 502, a processor 504, a detector 506 and either an internaldisplay 508 or an external display 512. A battery 510 may be used topower processor 504, detector 506 and display 508/512. Detector 506 isfor example an accelerometer or a Hall Effect sensor. Display 508/512 isfor example a liquid crystal display and/or a small speaker (e.g., thatemits voice annunciations or other sounds generated by processor 504).

FIG. 6 shows one part of an exemplary body bar 602 with body bar sensingsystem 500 attached; a weight 604 and a retaining clip 606 are alsoshown to secure weight 604 onto body bar 602 (note, somebody bars use noweights but weight is shown in FIG. 6 for illustrative purposes). Bodybar 602 may represent a work out bar used by people in the gym, or abarbell, or other similar apparatus that requires a number ofrepetitions in exercise. FIG. 7 shows body bar 602 in an embodiment withanother body bar sensing system 500 that secures weight 604 onto bodybar 602. That is, sensing system 500 in addition operates as retainingclip 606, FIG. 6.

FIGS. 5, 6 and 7 are best viewed together with the followingdescription. Housing 502 attaches to body bar 602 as shown in FIG. 6 oras shown in FIG. 7. Processor 504 utilizes detector 506 to determinewhen system 500 (as attached to body bar 602) has performed onerepetition; it then informs the user, via display 508/512 for example,of a number of repetitions (or whether the user has performed the rightnumber or any other number of planned repetitions as programmed intoprocessor 504).

Where display 512 is used (i.e., remote from housing 502), a wirelesstransmitter (not shown) may be included within housing 502 to remotelyprovide data from processor 504 to remote display 512 (as shown indotted outline). Where display 508 is integral with housing 502, thendisplay 508 provides a visual display for a user when housing 502attaches to the body bar. In one embodiment, display 512 (shown indotted outline) is part of a watch (or a MP3 player or a cell phone)that may be seen when worn or used by the user when performingexercises; and measurements determined by processor 504 are transmittedto the watch (or to the MP3 player or cell phone) for display upondisplay 512.

Processor 504 may operate under control of algorithmic software 505(which is illustratively shown within processor 504 although it mayreside elsewhere within housing 502, such as stand alone memory withinhousing 502). Algorithmic software 505 for example includes algorithmsfor processing data from detector 506 to determine the repetitionsperformed by a user of body bar 602.

FIG. 8 shows one exemplary process 800 performed by processor 504. Instep 802, detector 506 samples a physical metric associated with bodybar 602. In an example of step 802, detector 506 is an accelerometer andthereby provides acceleration as the physical metric. In another exampleof step 802, detector 506 is a Hall effect sensor which detectsinversion (and thus repetition) of bar 602. In step 804, processor 504processes the physical metric to assess whether the metric indicates arepetition of body bar 602. In an example of step 804, processor 504evaluates the acceleration to determine if body bar 602 has been raisedor lowered within a certain time interval. In step 806, repetitioninformation is displayed to the user. In an example of step 806, thenumber of repetitions is relayed remotely (wirelessly) to a watch thatincludes display 512. That watch may also include a processor to storedata and inform the user of repetitions for workouts, over time.

FIG. 9 shows one exemplary system 900 for unitlessly assessing activityof a user. System 900 has a processor 904, a detector 906 and a battery908 within an enclosure 902 (e.g., a plastic housing). System 900 mayinclude a display 910 for displaying unitless units to the user.Alternatively (or in addition), a remote display 912 is used to displaythe unitless units; in this case, enclosure 902 includes a wirelesstransmitter 913 in communication with, and controlled by, processor 904,so that transmitted unitless assessment numbers are sent to remotedisplay 912.

In an embodiment, detector 906 is an accelerometer and processor 904determines a value representing an activity level of the user of system900 for display on display 910 or display 912. The accelerometer is forexample positioned within housing 902 so that, when housing 902 isattached to a user, accelerometer 906 senses motion perpendicular to asurface (e.g., ground or a road or a floor) upon which the user moves(e.g., runs, dances, bounces). Data from the accelerometer is forexample processed in the frequency domain as power spectral density(e.g., by frequency binning of the data). Multiple accelerometers (e.g.,a triaxial accelerometer) may also be used as detector 906—for exampleto sense motion in other axes in addition to one perpendicular to thesurface—and then processed together (e.g., in power spectral densitydomain) to arrive at a unitless value (as described below).

Processor 904 may utilize one or more algorithms, shown as software 905within processor 904, for processing information obtained from detector906 to assess the activity of the user. For example, processor 904 mayperiodically sample detector 906 to measure acceleration forcesexperienced by the user (when enclosure 902 is attached to the user,e.g., at the user's belt or shoe). Processor 904 may then process theseforces to assess the activity level of the user. This activity level mayrepresent effort exerted by the user when skiing.

The following represents a typical use of system 900, in an embodiment.In this example, detector 906 is one or more accelerometers. First,processor 904 determines when system 900 is in use, for example bysensing movement of housing 902 that corresponds to known activity(e.g., skiing or running). Alternatively, system 900 includes a button915 that starts processing (in which case, separate determination of aknown activity is not necessary). In an embodiment, button 915 islocated proximate to display 912, and communicated wirelessly withprocessor 904. In this case, wireless transmitter 913 is a transceiverand button 915 includes a transmitter or a transceiver.

Once processor 904 knows (by sensing motion) or is notified (by button915) that system 900 is operating in the desired activity, then itcollects data over a period of that activity—for example over 1 hour (atypical aerobic hour), 4 hours (a typical long run), 8 hours (a typical“ski” day) or over one full day, each of these being typical sportactivity periods; however any time may be used and/or programmed insystem 900. In an example, processor 904 integrates power spectraldensity of acceleration over this period of time to generate a number.This number in fact is a function of g's, frequency units and time,which does not make intuitive sense to the user. For example, consider aprofessional athlete who snowboards down difficult, double diamondterrain for eight hours. When system 900 measures his activity over thisperiod, his number will be high (e.g., 500 “units” of power spectraldensity) because of his extreme physical capabilities. Then, when a lesscapable user uses system 900, a number of, e.g., 250 units may begenerated because the user is not as capable (physically and skilled) asthe professional. Therefore, in this example, an expected maximumnumber, shown as MAX 914 within processor 904, may be set at 500. Adisplay range, shown as RNG 916 within processor 904, may also bedefined such that system 900 may display a unitless value that isrelative to the maximum number. Continuing with the above example, ifRNG 916 is set to 100, system 900 displays a unitless value of 100 forthe professional athlete and a unitless value of 50 for the less capableuser (i.e., the less capable user has a 50% value of the professionalathlete). By setting RNG 916 to other values, the displayed output rangeof system 900 may be modified.

In one example of use, system 900 is formed as a wrist watch tofacilitate attachment to a child's wrist. System 900, when worn by thechild, may then determine the child's activity level for the day. Inanother example of use, system 900 may be attached to a person's limbthat is recuperating from injury (e.g., sporting injury, accident and/oroperation etc.) such that system 900 may determine if the limb isreceiving the right amount of activity to expedite recovery.

In another example of use, two skiers each use a system 900 when skiingfor a day. The first skier, who is experienced and athletic, skisdifficult ski runs (e.g., black double diamonds) all day, whereas thesecond skier is less experienced and skis easy runs (e.g., green runs)all day. At the end of the day, the first skier has a unitless activityvalue of 87 and the second skier has a unitless activity value of 12.Thus, these unitless activity values indicate the relative activitylevels of each skier.

FIG. 10 shows a flowchart illustrating one process 1000 for determiningand displaying a unitless value representative of a user's activity.Process 1000 may represent algorithms within software 905 of FIG. 9, forexample, to be executed by processor 904. In step 1002, process 1000clears a period accumulator. In one example of step 1002, processor 904,under control of software 905, clears period accumulator 918. In step1004, process 1000 samples the detector to obtain data. In one exampleof step 1004, processor 904 periodically samples detector 906 over asample period to determine data representative of the user's activityfor that period. In step 1006, process 1000 processes the data of step1004 to determine a number. In one example of step 1006, processor 904integrates power spectral density of acceleration sampled in step 1004over the sample period of step 1004 to generate a number. In step 1008,the number determined in step 1006 is added to the period accumulator.In one example of step 1008, processor 904 adds the number determined instep 1006 to period accumulator 918. In step 1010, process 1000determines a unitless activity value from the accumulator. In oneexample of step 1010, processor 904 converts the accumulated value to adisplay value based upon MAX 914 and RNG 916. In step 1012, process 1000displays the determined unitless activity value. In one example of step1012, processor 904 sends the determined unitless activity value todisplay 912 via wireless transmitter 913. Step 1014 is a decision. If,in step 1014, the activity period for display has ended, process 1000terminates; otherwise process 1000 continues with step 1004. Steps 1004through 1014 thus repeat until the desired activity period is over.

Changes may be made to this application without departing from the scopehereof. It should thus be noted that the matter contained in the abovedescription or shown in the accompanying drawings should be interpretedas illustrative and not in a limiting sense. The following claims areintended to cover all generic and specific features described herein, aswell as all statements of the scope of the present method and system,which, as a matter of language, might be said to fall there between.

What is claimed is:
 1. A system comprising: a detector that sensesactivity of a user; and a processor that: processes sensed activity datafrom the detector during an activity period to determine a numberrepresentative of the sensed activity data during the activity period;and generates a unitless activity value based on a comparison of thedetermined number and an expected maximum number for the activityperiod.
 2. The system of claim 1, wherein: the processor identifies aparticular activity of the user; and the processor identifies theexpected maximum number for the activity period based on the identifiedparticular activity.
 3. The system of claim 2, further comprising abutton, wherein the processor identifies the particular activity basedon at least one press of the button.
 4. The system of claim 2, whereinthe processor identifies the particular activity based on at least aportion of the processed sensed activity data.
 5. The system of claim 1,further comprising a display that displays the generated unitlessactivity value.
 6. The system of claim 5, wherein the processor repeatsthe processing and determining for a plurality of consecutive activityperiods.
 7. The system of claim 1, further comprising an enclosure thathouses the detector and the processor.
 8. The system of claim 7, furthercomprising a display that displays the generated unitless activityvalue, wherein the enclosure houses the display.
 9. The system of claim1, further comprising: a wireless transmitter; an enclosure that housesthe detector, the processor, and the wireless transmitter; and a displayexternal to the enclosure that: receives the generated unitless activityvalue via the wireless transmitter; and displays the generated unitlessactivity value.
 10. The system of claim 1, wherein the processorprocesses the sensed activity data from the detector during the activityperiod to determine the number by integrating power spectral density ofacceleration data of the sensed activity data over the period of time ofthe activity period.
 11. The system of claim 1, wherein the processorgenerates the unitless activity value by: determining a ratio based onthe comparison of the determined number and the expected maximum numberfor the activity period; and multiplying the determined ratio by a rangenumber.
 12. The system of claim 1, wherein the sensed activity data isindicative of a number of physical repetitions.
 13. The system of claim1, wherein the unitless activity value is based on an intensity of thesensed activity.
 14. The system of claim 1, wherein the unitlessactivity value is based on a length of the activity period.
 15. Thesystem of claim 1, wherein the sensed activity data is indicative of atleast two different activities.
 16. A system comprising: at least onesensor that detects an activity of a user; and a processor that:determines a user activity value by processing the detected activity;ratios the determined user activity value to another activity value; andreports a unitless activity value based upon the ratio.
 17. The systemof claim 16, wherein the at least one sensor comprises at least oneaccelerometer.
 18. The system of claim 16, wherein the processordetermines the user activity value by determining power spectral densityof the detected activity over a frequency range.
 19. The system of claim16, wherein the other activity value corresponds to a predeterminedactivity value of a professional athlete for another activity associatedwith the activity.
 20. The system of claim 16, further comprising: awireless transmitter; an enclosure that houses the at least one sensor,the processor, and the wireless transmitter; and a display external tothe enclosure that: receives the reported unitless activity value fromthe processor via the wireless transmitter; and displays the receivedunitless activity value.
 21. A system comprising: a detector; anaccumulator; and a processor that: samples the detector to obtain dataduring a time period; processes the obtained data to determine a numberrepresentative of the obtained data for the time period; adds the numberto the accumulator; and determines a unitless activity value based uponthe number in the accumulator and an expected maximum number.
 22. Thesystem of claim 21, wherein the processor repeats the sampling,processing, adding, and determining a plurality of times during the timeperiod.
 23. The system of claim 21, further comprising a display thatdisplays the determined unitless activity value.
 24. The system of claim21, wherein the processor processes the obtained data by determiningpower spectral density of the obtained data over a frequency range. 25.The system of claim 21, wherein the processor determines the unitlessactivity value by: determining a ratio based on a comparison of thenumber in the accumulator and the expected maximum number; andmultiplying the determined ratio by a range number.
 26. The system ofclaim 21, wherein the obtained data is indicative of a number ofphysical repetitions.
 27. The system of claim 21, wherein the unitlessactivity value is based on an intensity of the obtained data.
 28. Thesystem of claim 21, wherein the unitless activity value is based on alength of the time period.
 29. The system of claim 21, wherein theobtained data is indicative of at least two different activitiesperformed by a user.
 30. The system of claim 21, wherein the time periodis at least eight hours.